Complete Dumb Cane Guide

16 Oct 2021

This stunning, striking, and easy-to-care-for houseplant is a must-have! The dumb cane is a great decorative piece and depending on its size can be placed on your table or floor.

We’re going to explore all of the care requirements, tips, and techniques to grow a thriving dumb cane.

Main Features

Its scientific name is dieffenbachia, and it comes in a variety of colors and types. It belongs to the Araceae family, the same one as the monstera plant.

This tropical-loving houseplant is native to South America and the Caribbean. Not only does it sprout visually striking leaves but it’s also a natural air purifier. It rids the surrounding air of formaldehyde and xylene.

Its large patterned leaves come in an array of colors, patterns, and types. We’ll take a quick look at some popular variations below.


There are just over 30 species of dieffenbachia and over 100 different cultivars. Let’s explore ten of the most exquisite and popular types.

  1. Dieffenbachia ‘Camille’: These have broad leaves with a pretty lime line running through the center, and dark green edges.
  2. Dieffenbachia ‘Camouflage’: Their leaves are a lush green with cream veins.
  3. Dieffenbachia ‘Rudolph Roehrs’: Its leaves are completely yellow covered in ivory splotches.
  4. Dieffenbachia ‘Tropic snow’: This variation has smaller leaves with more variegation.
  5. Dieffenbachia ‘Compacta’: There are many creamy splotches and speckles covering their green leaves with a yellow center.
  6. Dieffenbachia ‘Honeydew’: Its leaves are absolutely stunning. They’re a golden yellow color with darker green edges.
  7. Dieffenbachia ‘Rebecca’: Their bright green leaves are framed with medium green edges.
  8. Dieffenbachia ‘Triumph’: This variety has light green leaves with a beautiful creamy-white vein running through the center. It also has dark green edges.
  9. Dieffenbachia ‘Tiki’: Its wavy green leaves are covered in gray, green, and white spots.
  10. Dieffenbachia ‘Mary’: These light green leaves have splotches of white and are covered in a variety of different shades of green.

How Big Does It Get?

The mature size of the dumb cane depends on its variety. We can divide its average size into three main height categories; 1 to 3 feet (30.5 – 91.4cm), 3 to 8 feet (0.9 – 2.4m), and 8 to 20 feet (2.4 – 6m).

Usually, dieffenbachia can grow up to 2 to 3 feet (61 – 91.4cm) wide.

How Fast Does It Grow?

Dumb canes are super-fast growers, adding on an extra 2 feet (61cm) in height each year until it reaches its mature size.

How Long Does It Live?

If well cared for the dumb cane can live for several years, usually around 5 years.

Is It Toxic to Cats and Dogs?

Be wary of the dumb cane as it is highly toxic. Just like the ZZ plant and peace lily, the dumb cane contains calcium oxalate in its sap. The calcium oxalate forms raphides which almost appear as tiny needle-like structures. These raphides cause harm and painful microtrauma which causes swelling and other symptoms.

Make sure to keep it out of your cats, dogs, and child’s reach. We’ll discuss the symptoms below.

Pets’ Symptoms

If your pet comes into contact with the sap its eyes may swell, water and itch, and a rash will appear on its skin.

Your cat or dog may experience a few symptoms when it ingests any part of the houseplant. Take a look at the list below.

  • Excessive drooling
  • Swelling of the throat and tongue
  • A burning feeling in its mouth

Contact your vet immediately if your pet has ingested the sap.

People’s Symptoms

Make sure to seek professional medical advice straight away if you or a child has ingested any part of the plant.

We’ve put together a list of symptoms to look out for:

  • Pain when swallowing
  • Loss of speech
  • Skin dermatitis
  • Vomiting
  • Swelling and burning of the tongue and lips

If your eyes come into contact with the sap they may become irritated causing corneal abrasions, and in very rare cases permanent eye damage.

Fun Fact: Dumb cane gets its “dumb” name due to the effects of its toxic sap. The poison causes a person to have difficulty speaking, and “dumb” use to refer to one who cannot talk.

Dumb cane - size, lifespan, toxicity, growth speed (infographics)

Dumb Cane Care

All houseplants need different care and environmental requirements. Let’s dive straight into how you can optimally care for a dumb cane.

How Often to Water

The dumb cane thrives when it is watered regularly, so make sure to keep a consistent watering schedule for this houseplant. It is very susceptible to overwatering and root rot, however, the soil does need to be moist.

Always check the soil’s moisture level before you water it as you don’t want to over- or underwater it. The soil must never dry out and should be kept slightly moist at all times.

During the warmer spring and summer months, you can water the houseplant 2 or 3 times a week. Once it’s cold during the winter and autumn months, you can reduce this to about once a week.

Top Tip: A general rule is that the top inch (2.5cm) of the soil must be slightly dry in between watering.


Due to the frequency of watering, the dumb cane needs quick and effective drainage. This can be achieved through proper potting mixes and drainage holes.

There are few key minerals that you can add to the potting mixture to ensure that it is well-draining and aerated. Try mixing in some perlite, vermiculite, and sharp sand.

It is imperative that the pot has 3 or 5 drainage holes at the bottom. This way all the excess water can easily flow out.

Your plant won’t survive if it’s sitting in saturated conditions, therefore, you’ll need to empty out the saucer after you have watered the dumb cane.

How to Prune

You should only prune your plant to remove any damaged foliage or maintain its shape and size. Ideally, you should trim the dumb cane during the springtime.

If you notice any yellow or brown leaves then use a pair of sterilized pruners to snip these leaves off. You can also prune off the top of the plant to keep its size manageable.

When trimming off a leaf always cut the stem at about a 45-degree angle and water the plant well afterward.

Top Tip: Always wear a pair of gardening gloves whenever you are trimming or cutting any part of the dumb cane because its sap is highly toxic.

How to Repot

Transplanting the dumb cane should be done about once a year during the springtime. Once its roots begin to grow out through the drainage holes then you know it’s time to repot the plant. Ideally, you should find a pot that is one size bigger than the previous container.

Follow the steps below:

  1. Loosen the soil by sliding a blunt knife around the pot’s edge and slide the dumb cane out.
  2. Brush off any soil still attached to the roots.
  3. Find a new pot and fill it with around 3 inches (7.6cm) of soil, and then place the dumb cane in the container.
  4. Use some more potting mix to fill in the surrounding areas and completely cover the roots.
  5. Water the plant deeply until it drips out the drainage holes.


Light Requirements

Dieffenbachia prefers medium to bright sunlight. It’s best to place it near a bright, sunny windowsill where it’ll soak in filtered sunshine.

The houseplant can survive shady areas but its growth will be stunted, however, it shouldn’t be placed in direct sunlight either. The color of the leaves will begin to fade when it is receiving too much sunshine.


The dumb cane thrives in well-draining soil. Ideally, it loves a slightly acidic potting mix with a pH level of 6.1 to 6.5. Avoid using any orchid potting mixtures or heavy soils.

It’s best to add in some humus, peat moss, or compost to ensure that the soil is nutrient-rich and light.

Try mixing together 1 part peat moss and 1 part potting mix for the perfect soil.


The dumb cane only requires to be fed about twice a month during its active growing seasons. There is no need to feed it during the cooler winter and autumn months.

Make sure to use a balanced water-soluble fertilizer such as 20-20-20. Additionally, you should dilute it to half its strength to avoid over-feeding your plant.

Top Tip: This houseplant absolutely loves a fertilizer high in nitrogen.

Pot Size and Type

A plastic pot with a few drainage holes is perfect for the dumb cane because it retains an adequate amount of water while also allowing for the water to drain out.

You can make use of a terracotta container, however, you’ll need to water your houseplant more frequently.

The container must be around one-third wider than the rootball’s diameter. This allows for the roots to have enough space while growing without becoming pot-bound.


Dieffenbachia flourishes in temperatures around 60 to 80°F (15.5 – 26.6°C). You will need to ensure that it doesn’t sit in temperatures below 60°F (15.5°C) for a prolonged period of time as its leaves may fall off.


This houseplant, like many others such as the spider plant, thrives in high humidity levels around 60%.

If you live in a particularly warm region then mist it twice a week during the summertime. You can also surround it with other houseplants, grow it in your steamy bathroom, or place a humidifier nearby.

Not everyone has a humidifier but there’s a great alternative. Find a shallow tray and place a few stones and some tepid water inside. Place your plant on top of the stones to increase the humidity levels surrounding the dumb cane.

Does It Grow Outside?

Dieffenbachia absolutely thrives outdoors during the summertime when it’s warm and grown in filtered sunshine. Ideally, it grows in USDA hardiness zones of 10 through 12. You’ll need to move the plant back indoors once temperatures begin to drop.

There are a few things to keep in mind when growing the dumb cane outside:

  • It needs to be misted more frequently to maintain humidity levels.
  • The soil may need to be watered more to ensure that it does not dry out.
  • The dumb cane must be placed in partial shade so that its leaves don’t burn.

Dumb cane - care, water, light, soil, pot, temperature, fertilizer (infographics)


Unfortunately, this seasonal bloomer rarely flowers indoors.

If by luck it does flower, you’ll see small white flowers resembling a folded leaf. The blooms tend to last for a while but are not that showy or spectacular.

You can increase the chances of your dumb cane flowering by adequately feeding it and making sure that it gets a decent amount of sunshine.

How to Grow It

You can easily grow and multiply your dumb cane collection through various propagation methods or by planting its seeds.

Follow the guides and steps we’ve set out below.

Dumb Cane Propagation

You can propagate your dumb cane in soil and water. It is best to do so during the springtime and always remember to use sterilized pruners or shears when cutting the plant.

In Soil

When propagating the dumb cane in soil, make sure to use fresh, nutrient-rich potting soil that is well-draining.

We’ve provided you with steps and guides for the various methods of propagation below.

Air Layering
  1. Use a sharp, clean knife to make a 2 inch (5cm) slit along the stem.
  2. Place a toothpick in the cut area to keep the slit open.
  3. Apply rooting hormone to the cut area and cover it with moist sphagnum.
  4. Take clear plastic wrap and form a small ball-like structure with the sphagnum moss around the cut area.
  5. Use a piece of string or tape to hold the ball in place.
  6. Once you notice any new root growth you can gently remove the plastic wrap and cut off the newly grown branch.
  7. Plant this branch in its own container with some potting soil and water it well. Place a clear plastic bag over the container.
  8. In about a month when the roots have developed, you can remove the plastic and care for as you would a mature dumb cane.
Stem Cuttings
  1. Use a sterilized blade to cut a stem that’s about 6 to 8 inches (15.2 – 20.3cm) long. Any leaves attached should be plucked off.
  2. Prepare a pot with 1 part peat moss and 1 part sand. Place the stem cutting horizontally in the soil where the bottom is covered but the leaf bud is not.
  3. Lightly water the cutting and place it by a sunny windowsill.
  4. In about 4 to 8 weeks, you can repot the cutting into a bigger home if needed.

Offsets or pups are sometimes produced by the mother plant. They are easily propagated in soil, just follow the steps below.

  1. Slide the dumb cane out of its pot and brush off the excess soil. You may need to rinse the rootball under a gentle stream of water.
  2. Cut off the pup but make sure that you don’t damage any roots or cut into the mother plant.
  3. Find a new pot and fill it with some nutrient-rich potting soil.
  4. Place the offset about 1 or 2 inches (2.5 – 5 cm) deep in the soil and water it well.
  5. Find a new home where it’ll receive ample amounts of indirect sunlight.

In Water

When propagating stem cuttings in water, it is important to use a clear glass in order to monitor the root growth, and use clean water to avoid any bacterial build-up.

  1. Use a sharp, clean pair of pruners to cut a 4 to 6 inch (10 – 15.2cm) long stem, and remove any leaves.
  2. Fill a clean jar with some cool water and place the stem cutting into the glass.
  3. You may need to change the water every 3 or so days so that algae doesn’t build up.
  4. Find a bright, sunny home to grow the cutting.
  5. In 4 weeks when new roots have developed, you can then repot the cutting in some well-draining potting soil.

Seed Planting

Growing a dumb cane from seed is relatively straightforward but you may need to be a tad patient as they can take some time to germinate.

  1. Find a shallow tray and fill it with 1 part peat moss and 1 part potting soil.
  2. Spread the seeds evenly across the mixture and mist it. The soil must be kept moist at all times.
  3. Place a plastic bag over the tray to retain moisture and increase humidity.
  4. Make sure the container is kept at around 70°F (21.1°C) to ensure the seeds germinate.
  5. You can transplant the seedlings into their own pots once they produce a leaf.

How to Revive It

Dieffenbachia can sometimes run into a few issues. You don’t need to freak out or worry too much as reviving this plant is simple. We’ll tell you exactly what may be the issue at hand and how to remedy any problems caused.

Why Is My Plant Turning Yellow?

If your dumb cane’s leaves are turning yellow and falling off then there are three reasons for this; aging, exposure to cool temperatures, or overwatering.

You don’t have to worry if one or two leaves yellow and drop off as this is a normal sign of aging. You should only be concerned when many leaves fall off at once.

Dumb canes require pretty warm conditions, so simply find a warmer home for your plant.

Keep in mind that this houseplant is susceptible to root rot, so overwatering can be detrimental to your plant’s health. You’ll need to wait until the soil has slightly dried out before watering it again and change your future watering schedule.

Brown Leaf Tips

The leaf tips begin to brown when the plant is either over- or underwatered. Always check the soil before you water your plant, if it’s still wet then you should wait until watering it.

If the dumb cane is being overwatered then only water it again when the top of the soil has dried. If the soil is too dry you’ll need to deeply water the plant and tweak your watering schedule.

Pale Leaves

Pale or faded leaves are due to exposure to direct sunlight. These harsh sun rays burn the leaves and cause the color and patterns to fade away.

This is easy to fix, all you have to do is to find a new home where the plant will receive indirect sunshine.

Soft Stems

Soft stems are a sign of root rot, which is caused by excessive overwatering. You’ll need to trim off any softened stems or roots and repot the dumb cane in some fresh, dry potting soil. Only water the plant in a couple of days to allow it some time to recover.

Wrapping Up

The dumb cane has vibrant and striking foliage that is worth caring for. It is relatively easy to look after as long as you know what to do. Always check that the soil is moist, the plant is placed in bright sunlight, and that it is fed well.

Remember to wear gloves when handling this toxic houseplant and please keep it out of your child’s reach.

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